Hand held TDS meter options

[Myka]

I currently have an HM Digital TDS-3 meter and I despise it. It is horrible to try to calibrate with the screwdriver that you move a billionth of a mm and the meter goes up by 50 ppm. The Hanna TDS-1 uses the same type of screwdriver calibration. I'm looking for something easier to calibrate.

The only hand held TDS meter that I know of that doesn't use a screwdriver for calibration is the HM Digital COM-100 meter. It is also top of the line, and rather pricey.

Anyone know of any other TDS meter that doesn't use that stupid screwdriver calibration?

EDIT: Just found the Hanna HI 98311 Waterproof Low Range meter self calibrates like their pH meters. Excellent! However, just as pricey as the HM Digital COM-100 meter!

EDIT 2: The Hanna Primo has automatic calibration with 1382 ppm fluid. It suggests 2% +/- accuracy, but I wonder how accurate it is when it is very close to 0? I will send email. This meter is only $20.

[Binare]

Walmart in the rv isle, costs 10 or 15 bucks if memory serves me correctly.

[Myka]

Originally Posted by Binare

Walmart in the rv isle, costs 10 or 15 bucks if memory serves me correctly.

How is it calibrated?

[sitandwatch]

The Walmart one does not have a calibration, turn it on stick it in the water and you get a reading.

[Myka]

Originally Posted by sitandwatch

The Walmart one does not have a calibration, turn it on stick it in the water and you get a reading.

Hmmm...I don't like that idea.

[Binare]

You hold the button till it reads zero, then put it in your water. Not entirely sure why calibration is necessary on some these. Out of liquid it should always read 0. The walmart one works good enough for our needs, filter replacement.

[Myka]

Originally Posted by Binare

You hold the button till it reads zero, then put it in your water. Not entirely sure why calibration is necessary on some these. Out of liquid it should always read 0. The walmart one works good enough for our needs, filter replacement.

Mine has read 15 ppm off when I have calibrated it. It always says 0 out of liquid. I want to change my filters when I get 1 ppm tds, not 15 ppm! Mostly I'm just sick of my particular TDS meter, and I'm looking for something different, but no I don't want to spend $80 on a tds meter! Just looking at other options.

[muck]

I have a Hanna Primo I will be posting Mindy.
Bought in 2007, used a couple times. Never did open the cal fluid pouch.
Pretty much mint condition, cept the batteries are dead. I'll check and see if I have some spare batteries kicking around tonight.

[Myka]

Originally Posted by muck

I have a Hanna Primo I will be posting Mindy.
Bought in 2007, used a couple times. Never did open the cal fluid pouch.
Pretty much mint condition, cept the batteries are dead. I'll check and see if I have some spare batteries kicking around tonight.

Excellent. Maybe I can nab it off ya when I come to Edmonton next.

[mike31154]

I just have a cheapo hand held as well and haven't bothered with calibration. My RODI system has the standard dual TDS meter and I've never cal'd that one either. One time I pulled a probe from the dual TDS job and compared the reading to the handheld, difference was about 10-15 ppm when reading my tapwater. If memory serves, the handheld read lower. My tap is around 210 with the handheld and 220 with the dual TDS probe. I think I tried both the dual TDS probes and they were both reading the same. That's the one I'm more concerned about, not the handheld, since the dual TDS is on my RODI. I'm pretty ok with trusting the dual to tell me when the TDS out of the DI stage starts to creep above 0. I'm kind of with Binare on this one, for our purposes do we really need to be tweaking these things for a few tens of ppm? Of course if I had access to a more accurate/pricey instrument, I'd certainly give it a go to compare.